When to Plant Fennel in Spring Valley, IL

One of the first steps you take when you are figuring out your gardening schedule is find your USDA Zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

A way of getting a good idea when you can plant fennel is to consult the USDA zone info for Spring Valley.


Planting Calendar for Fennel

Frost tolerance for fennel: Very tolerant of frost.
When to plant: Up to 7 weeks before last frost.

Fennel are very cold tolerant which tells us that you can start planting them much earlier than other frost tender plants.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant fennel
Possibly ok, but a risky time to plant fennel
Probably not a good time to plant fennel

The earliest that you can plant fennel in Spring Valley is February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant fennel and expect a good harvest is probably September. You probably don't want to wait any later than that or else your fennel may not have a chance to fully mature. You can get started a couple of weeks earlier by starting your fennel indoors.

Last Frost Date

The average date of last frost is April 15 in Spring Valley. In the coldest months of winter you can expect an average low temperature of -15°F.

Keep in mind that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Spring Valley and it is different every year. Since half of the time in Spring Valley you get surprised by a frost after April 15 be ready to protect your fennel in the event of a late frost.

USDA Zone Info for Spring Valley

Here is the info for USDA Zone 5b.

Average Date of Last Frost (spring)April 15
Average Date of First Frost (fall)October 15
Lowest Expected Low-15°F
Highest Expected Low-10°F

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Spring Valley

You may be interested in your other planting guides for Spring Valley.